Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service life.Especially in cold region,cracking caused by low temperature is the main distress for...Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service life.Especially in cold region,cracking caused by low temperature is the main distress form.This paper discussed the effect of aggregate gradation on the low temperature performance in asphalt paving mixtures.A total of 11 asphalt mixtures with 11 different aggregate gradations and one asphalt binder content were studied.Volumetric properties of the coarse aggregate and asphalt mixtures showed aggregate grading has a significant impact on the degree of aggregate interlock in asphalt mixtures.A trend is existed in the low temperature performance with the change of gradation.With the aid of mathematic statistics,it indicates gradation affects the low temperature performance significantly.The findings also indicate the relationship between the degree of aggregate interlock in asphalt mixtures and the low temperature performance:With the stone-to-stone contact developed,the mixture has a high energy to resist contract and deformation at low temperature.The properties of fine aggregate and asphalt play an important part in resisting low temperature cracking in floating structure.But it provides lower energy to resist low temperature cracking compared to the skeleton structure.展开更多
Chip seal is widely used for preventive maintenance to mitigate pavement deterioration,but it is prone to aggregate loss during pavement service.To further promote the development and application of chip seals in road...Chip seal is widely used for preventive maintenance to mitigate pavement deterioration,but it is prone to aggregate loss during pavement service.To further promote the development and application of chip seals in road engineering in China,the research progress of the adhesion behavior of aggregate and binder in chip seals was reviewed in this paper,focusing on the adhesion mechanism of emulsified asphalt and alkaline aggregate.The Influencing factors and evaluation methodology of chip seals'aggregate adhesion behavior were also discussed.The results demonstrate that the adhesion process between emulsified asphalt and alkaline aggregate is divided into three processes including infiltration,demulsification,and cluster,which is more complicated when compared to hot asphalt.When designing a chip seal,not only the characteristics of single material should be paid attention to,but also the combination of binder and aggregate matters a lot.To form good adhesion between aggregate and asphalt binder,various influencing factors such as material selection,design method,and construction technical index should be considered comprehensively in the whole design,construction,and operation process.Three methods for evaluating adhesion behavior are summarized,including macroscopic adhesion performance tests,image analysis technology,and model prediction.It is not objective to evaluate the aggregate adhesion behavior of chip seal only by a single evaluation method.A comprehensive evaluation based on the micro-macro multi-scale method should be considered in the future.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.50778057)the Research Fund for the Doctoral Program of Higher Education(Grant No.20060213002)
文摘Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service life.Especially in cold region,cracking caused by low temperature is the main distress form.This paper discussed the effect of aggregate gradation on the low temperature performance in asphalt paving mixtures.A total of 11 asphalt mixtures with 11 different aggregate gradations and one asphalt binder content were studied.Volumetric properties of the coarse aggregate and asphalt mixtures showed aggregate grading has a significant impact on the degree of aggregate interlock in asphalt mixtures.A trend is existed in the low temperature performance with the change of gradation.With the aid of mathematic statistics,it indicates gradation affects the low temperature performance significantly.The findings also indicate the relationship between the degree of aggregate interlock in asphalt mixtures and the low temperature performance:With the stone-to-stone contact developed,the mixture has a high energy to resist contract and deformation at low temperature.The properties of fine aggregate and asphalt play an important part in resisting low temperature cracking in floating structure.But it provides lower energy to resist low temperature cracking compared to the skeleton structure.
基金supported by National Natural Science Foundation of China(No.52108396)Open Fund of Key Laboratory of Road Structure and Material of Ministry of Transport(Changsha University of Science and Technology)(No.kfj210301)。
文摘Chip seal is widely used for preventive maintenance to mitigate pavement deterioration,but it is prone to aggregate loss during pavement service.To further promote the development and application of chip seals in road engineering in China,the research progress of the adhesion behavior of aggregate and binder in chip seals was reviewed in this paper,focusing on the adhesion mechanism of emulsified asphalt and alkaline aggregate.The Influencing factors and evaluation methodology of chip seals'aggregate adhesion behavior were also discussed.The results demonstrate that the adhesion process between emulsified asphalt and alkaline aggregate is divided into three processes including infiltration,demulsification,and cluster,which is more complicated when compared to hot asphalt.When designing a chip seal,not only the characteristics of single material should be paid attention to,but also the combination of binder and aggregate matters a lot.To form good adhesion between aggregate and asphalt binder,various influencing factors such as material selection,design method,and construction technical index should be considered comprehensively in the whole design,construction,and operation process.Three methods for evaluating adhesion behavior are summarized,including macroscopic adhesion performance tests,image analysis technology,and model prediction.It is not objective to evaluate the aggregate adhesion behavior of chip seal only by a single evaluation method.A comprehensive evaluation based on the micro-macro multi-scale method should be considered in the future.
